Conventionally, a three-dimensional image display device for displaying a three-dimensional image has been used for various purposes, such as computer games, CAD systems, airplanes, and medical devices etc. The following explains a typical principle for providing a user with a three-dimensional image.
Display of a three-dimensional image is carried out by capturing an image at plural different angles, and then displaying the plurality of captured images with parallax with respect to both eyes of the user. Accordingly, when capturing image data for performing three-dimensional image display, a plurality of image pickup sections are placed at different positions so that shooting directions (light axes) of the respective image pickup sections intersect with each other on the object of shooting. The following describes three typical methods for offering a three-dimensional image to the user in this manner.
In the first method, with a general image display device, a red image is displayed to the right eye of the user, and a blue image is displayed to the left eye of the user. In the meantime, the user wears glasses with a blue film for the right eye and a red film for the left eye so that the right eye of the user sees only the red image while the left eye of the user sees only the blue image. While the user sees the blue image with the left eye and sees the red image with the right eye, he/she also recognizes a plurality of images with parallax. As a result, the user sees a three-dimensional image by optical deception.
In the second method, two image display devices are used respectively for the right eye and for the left eye, provided with in front thereof polarization plates whose polarizing directions intersect with each other. Then, the images from these image display devices for the right eye and for the left eye with different polarizing conditions are unified by a half mirror. Meanwhile, the user wears glasses with separate polarization plates for the right eye and the left eye, whose polarizing directions intersect with each other, so that the right eye of the user sees only the image from the image display device for the left eye while the left eye of the user sees only the image from the image display device for the right eye. As a result, the right eye and the left eye of the user individually see images different in polarizing condition, so that the user sees a three-dimensional image by optical deception.
In the third method, with a general image display device, plural images with parallax are displayed in turn at certain time intervals. Meanwhile, the user wears glasses with shutters which open and close at the time intervals identical and synchronized with the time intervals above for switching the plural images. As a result, the right eye and the left eye of the user individually see images different in parallax, so that the user sees a three-dimensional image by optical deception.
As an example of such display devices for taking and displaying a three-dimensional image, Japanese Laid-Open Patent Application Tokukaihei 11-55693/1999 (published on Feb. 26, 1999) discloses a still image camera including a plurality of image pickup sections. In this device, the plurality of image pickup sections simultaneously film the same object so as to take and display a three-dimensional image.
Incidentally, as with the folding image information terminal device shown in FIG. 14, a typical conventional information terminal device is made up of a display section 101 with a display 100, and an operation section 103 with an operation button 102. With this structure, Japanese Laid-Open Patent Application Tokukaihei 10-108152/1998 (published on Apr. 24, 1998) realizes an image information terminal device for taking and displaying a three-dimensional image, by providing, as shown in FIG. 14, a plurality of image pickup sections 104 and 105 in the display section 101 having the display 100.
However, to capture an object of three-dimensional display, it is necessary to capture a plurality of images of one object with parallax of certain extent. For this reason, the respective image pickup sections for capturing a three-dimensional image are preferably placed with a specific distance. Generally, it is preferable to determine this distance to be similar to the interval between both eyes of a human.
Here, in the structure shown in FIG. 14, the image pickup sections 104 and 105 are provided in the display section 101. However, in case of adopting such a folding information terminal device for a small-sized device such as a mobile phone, there arise some mechanical difficulties to place the image pickup sections 104 and 105 in the display section 101, while providing a specific distance between them. Further, for a conventional folding information terminal device, the arrangement of providing image pickup sections with a specific distance has not been realized in any sizes of device.